Evaporative cooling system for internal-combustion engines



Feb. 19, 1952 INTERNAL-COMBUSTION ENGINES 2 SHEETSSHEET 1 Filed June 8, 1950 INVENTOR W ON v I l I I I l I I I l I I I I l I I l I l I I mm u u n umj .I\\ ll Wk 0 lllll l PIP-in w F m N mm L W i! mm 5W 4 m l N m w \NWm, H a W NW n ATTORNEY Feb. 19, 1952 A w POPE, JR 2,586,562

EVAPORATI'VE ('JOOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Filed Jime 8, 1 950 2 SHEETS-SHEET 2 ATTORNEY Patented Feb. 19, 1952 EVAPORATIVE COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Arthur W. Pope, Jr., Waukesha, Wis., assignor to Waukesha Motor Company, Waukesha, Wis.

Application June 8, 1950, Serial No. 166,893

12 Claims. 1 This invention relates to cooling systems for internal combustion engines, and more particularly to evaporative type systems wherein coolant is caused to circulate by both thermal siphon action and by the energy of steam discharging from the engine cylinder Water jacket.

It is an object of this invention to provide an improved evaporative type cooling system wherein steam generated in the engine cylinder jacket flows through a duct wherein is established a region of high velocity, and a region of pressure reduced beneath the normal operating pressure of the system. A circulatory path is provided from the outlet of said duct through steam condensing and condensate cooling apparatus to the reduced pressure region of the duct whereby steam and water vapor issuing from the water jacket are condensed and cooled during fiow through the circulatory path resulting from both thermal siphon action and the suction or negative pressure created in the duct.

Another object of the invention is to provide an improved evaporative type cooling system wherein coolant is delivered to the engine cylinder water jacket by the impact force of intermixed water and steam flowing at high velocity through a restricted passage.

Another object of the invention is to provide an improved evaporative type cooling system wherein the coolant is delivered to the engine cylinder water jacket in proportion to the velocity of the steam discharged therefrom whereby substantially constant temperature conditions are maintained during operation of the engine under various load conditions.

Another object of the invention is to provide an improved evaporative type cooling system wherein a Venturi jet circulator is employed for increasing the velocity of the stream flow and producing a region of reduced pressure to enhance the flow of the coolant both through a condenser-cooling flow circuit andthrough a flow path comprising the engine cylinder water jacket.

Another object of the invention is to provide an improved evaporative cooling system utilizing a Venturi jet circulating device formed by an annular member adapted to be inserted within a steam duct, said device having an interior wall.

A further object of the invention is to provide an improved evaporative type cooling system which functions in an eflicient manner without the use of pumps, check valves, or other accessories having movable parts, and which'permits the radiator to be placed in a conventional vertical position adjacent to an internal combustion engine.

A still further object of the invention is to provide an improved evaporative type cooling system wherein reserve cooling capacity 'is provided to absorb the residual heat of the engine after operation has been terminated, thereby eliminating the blowing off of steam and the loss of coolant from the system.

The invention also resides in certain novel structural characteristics which facilitate the carrying out of the foregoing objects and which contribute both the efficiency of the improved evaporative type cooling system and toits simplicity of construction as well as to the dependability of its operation.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a view partly in elevation and partly in section showing an internal combustion engine provided with the improved evaporative cooling system;

Figure 2 is a cross sectional view taken on line 2-2 of Figure 3 disclosing an alternative construction from the discharge passage through which steam flows from the engine cylinder water jacket; and v Figure 3 is a cross sectional view taken on line 33 of Figure 2. I

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiments. It is to be understood, however, that I do not intend to limit the invention to such disclosure for I aim to cover all modifications and alternative constructions falling within the spirit and scope of the invention as defined in the appended claims.

Referring to Figure 1 of the drawings, reference numeral 10 represents a cylinder block of an internal combustion engine identified by reference numeral 12. The cylinder block H3 is pro vided with a plurality of cylinders indicated generally by reference numeral I l about which a cylinder water jacket i6 is positioned in a conventional manner. An outlet I8 is provided in the upper portion of the engine cylinder water jacket 85 through which steam and Water vapor generated within the water jacket is discharged in a generally upward direction. A duct 26 having the inlet thereof in communication with the outlet of the water jacket is disposed in a vertical direction directly above the water jacket and serves as a conduit through which flow the steam and water vapor issuing fro'in the water jacket. An orifice 22 is located in the wen of duct Zil intermediate the inlet and the outlet thereof having a connection thereto which is connected in the circulatory path of the coolant in a manner which w-ill'be hereinafter more fully described; M 1

A steam condenser tank 24 is positioned immediately above the duct ZII With the-St'eam inlet 25 which is located in the lower po'rtionthereoi; in communication with the outlet oi the duct. The condenser tank 24 is provided with an outlet 28 located in the upper portion of the condenser chamber which serves as an egress for the coolant during the operation of: the cooling system.

A radiator indicated; generally by reference numeral 30 is provided in-the system; and isposi tioned adjacent to theengine in'a; conventional man rs t a i n rpih ra r mn ll e eic 32 m bewnven en r.positi ne create a flow of cooling medium through the air pasa s. of he c r 31!; nd; ear-maths .adiec t nc n d s rf s iflheicr n e t .bleekl l and w r ,J' I o heii ib rnai. ,cq bus o ensi 2 Th a ia qr 9. siprevid d w h a rnh ad nd a; ner. head 3 b twe which the core I 34 is p9sitioned.. The. upper header 33 is provided with an inlet 4!! which is connected by a pipe orother conduit uteri the outlet 8 of t nseri li- Th lower header 38 is provided with an outlet 44 which connected by a 'condensat'e return pipeorother conduit 46 to the orifice '22 ldcated, in the wall of duct 20. n

The engine cylinder water jacket [6 is-provided with an inlet 48positioned inthe lower. portion of the jacket and a feed linjl'l is "oinniected thereto through which coolant is sup d to, -the interior of the Water jacket. rue cool is supplied to feed line 50 from aram. tub'e iden ified by reference numeral 52., The remain co'mprises a vertically extending tube section 54 having the inlet 56 thereof extending within meme let of duct 20 and directed toward thepa'th o'fsteam issuing from butlet'le of wate jacketls. The tube section 54 communicates with fee line 50 so that a portion of the coolant flowing through duct 20 is conveyed to the wvaterjacket it by the impact pressure of the steam and estiant. A venting orifice 58 is positioned in ram tube 52 so that gases entrapped Within the rain tube during the filling of the system may be vented into the interior of condenser tank 24.

The upper header 36 of the radiator 38. is provided with a filler opening 60 by which water or other liquid coolant may be introduced into the system; The filler opening is covered 'by a closure cap 62 which is provided with a venting orifice S4.

The filler opening 60 is providedwithga valve '66 which is normally biased to close the fillerjope nfing by compressing spring 68 when closure cap 52 is secured in position by cooperating threads located on the headerand closure cap.

The normal cold water level of the coolant in the system just described is indicated by line A-A, and lies just below the level of the bottom of pipe 42 which connects the chamber of condenser tank 24 with the upptr header 3B of the radiator. The remaininginterior portions of the,

system, including the engine cylinder water jacket l6, duct 20, feed line 55, condensate return pipe 46, and substantially all of core 34 of the radiator 30, are normally filled with water. Due to the fact that the pipe connection 42 between the chamber of condenser tank 24 and the upper header 36 of the radiator is unfilled, no circulation of. the coolant occurs until the water in the engine cylinder jacket reaches the boiling point, at which time the formation of steam bubbles in the engine cylinder jacket which rise through duct 20; displaces-suificient water in the cylinder jacketto raisethe water level above the bottom of the pipe 42 which establishes a continuous flow path for the liquid coolant. The coolant at an elevated temperature will then flow from the condenser tank. 24 through pipe 42 to the upper header 3B and pass through the radiator core 34 to the lower header 38. The liquid as it is cooled in this heat exchange device will descend to lower header 38 andwill-flow-th-rough the outlet-.45 thereof into the condensate return pipe t5 and through orifice 22 into, duct 2 0. As theboiling of the Water in theengine cylinder jacket Iii-.increases with increase cf engine load, the velocity of the steam flowing through duct 21 will increase and will cause-a reduction of the pressure below the normal ambientpressureof the system by aspirator action within the duct in the vicinity of orifice 22. The lowering of the pres;- sure in the region of orifice 2 2 producesin effect a suction or negative pressure which causes the ambient or normal pressure of the system to force condensate from the radiator through conden; sate return pipe 46 andorificeil into duct 26 where it will intermix with the steam issuin from outlet 18 of the engine cylinder jacket. Intermiking of the cooled condensate and steam results in the condensation ofthe steam with the liberation of heat whereby the temperature, of the liquid coolant is increased.

As the. hot coolant flowsthi'ough the aforedescribed circulatory path from condenser tank 24, through pipe 42 and through core 340i radiator 30, it is cooled anditsdensity is thereby increased. The coolant thereupon flows downwardly due to its increased density into lower header 33 and through condensate return pipe 46 and orifice 22 into ductlih Thus the flow of coolantto duct 20 is aided by the thermal siphone ingeffect which results from the cooling of the liquid in the system in addition to the aspirator action created by the steam flow induct '20. by virtue of which a negative pressure is created therein to induce the flow of coolant.

Coolant supplied from a zone in duct 20 in which. condensate and steam. are intermixed, is circulatedto the lower portion of engine jacket I6 through feed line 50. The new of coolant through feed line 50 is efifected by the impact pressure of the steam and condensate flow within opening 56 of tube section 54 of ram tube 52'. The'magnitude of the impact pressure is dependent upon the velocity of the steam flowing through outlet f8 and is suflicient to forcecoolant mm the inlet of the ram tube, through reed line-50 into the lower'portion of engine cylinder jacket IE to maintain the jacket filled with coolant during all conditions of engine operation.

Airwhichmay be entrapped within vertically positioned tube section 54 of the rain tube during the filling of the cooling 'sys'temis released through the venting o ifice 158gto the interior of the condenser tank 24 duringifilling of the 0601- ing system. The venting orifice 58 is formed with a small opening relative to the inlet of the ram tube so that leakage through the venting orifice does not adverselyafiect the operation of the system in forcing coolant to the engine water jacket.

The ambient pressure acting upon the surface of the liquid within the cooling system is preferably maintained slightly above the value of atmospheric pressure. Spring pressed valve 66 serves to maintain the filling opening 60 closed and to provide the increased pressure on the coolant within the system. The provision of operating the system under a pressure slightly above atmospheric pressure serves to prevent breathing of the system and eliminates the loss of coolant in the form of water vapor and steam from the system.

It may be advantageous in the cooling systems of certain types of internal combustion engines to increase the velocity of steam flow issuing through duct 20 and thereby obtain a relative greater negative pressure in the reduced pressure region of the connection between the engine cylinder jacket and the condenser chamber. Additionally, the increased velocity will provide a greater impact pressure at the inlet of the ram tube and thus increase the flow of coolant to the engine water jacket. My invention contemplates the operation of the cooling system with an increased steam velocity obtained by the use of a Venturi jet circulator through which the steam passes from the engine water jacket l6 to condenser tank 24. The Venturi passage in the form of an injector or jet pump may be formed separately and used in lieu of duct 20 or the Venturi passage may be provided by a Venturi insert which is utilized in conjunction with duct 20 as shown in Figure 1. A Venturi insert illustrated' in Figure 2 of the drawings has been found to be very efiicient in my improved cooling system, and as is indicated in the drawing, the insert is formed to be positioned and secured within the duct through which steam is discharged from the engine cylinder water jacket.

The improved insert formed with a Venturi passage therethrough comprises an annular member 10 which is adapted to be secured within duct and extends between the inlet and outlet thereof. Annular bosses or extensions H provided adjacent to the inlet and outlet of the insert engage the wall of duct 20 to maintain the insert in place. Annular member I0 is provided with a series of apertures 12 which extend around the wall of the member adjacent to the inlet side thereof when the member is positioned within duct 20. The wall of annular member 10 diverages in the direction of the stream fiow and the most restricted portion of the passage is provided in the area wherein apertures J2 are located. A flared entrant portion is provided between the terminal end of the Venturi insert and the restricted portion wherein the apertures 12 are positioned. The walls of duct 20, annular bosses H and the wall of the insert form an annular chamber or passage between apertures 12 and orifice 22 through which coolant flows. The annular member is secured Within duct 20 by the use of pins 14 or other suitable fastening devices which extend through the member into the wall of the duct.

When the annular member is inserted within duct '20, a fiow path exists between inlet orifice 22 and apertures I2 whereby coolant flowing through orifice 22 will pass through the orifices 12- into the flow stream passing through the annular member. The placement of the annular member 10 within duct 2!] creates a Venturi flow passage for steam being discharged from the engine cylinder jacket and the steam jet passing the restricted area wherein apertures 12 are positioned creates a region of negative pressure which aids the introduction of condensate flowing in pipe 46 through orifices 22 and 72 into the stream of steam wherein it intermingles with the steam. The steam is thus condensed during which it gives up heat whereby the temperature of the condensate is elevated. The coolant after the temperature thereof has been increased flows through the cooling path in the manner aforedescribed. The impact of the intermixed steam and condensate in inlet 56 of ram tube 52 causes a portion of the coolant to be directed through feed line 50 to the bottom portion of the engine cylinder jacket in the manner which has previously been discussed. It will be apparent that the use of the Venturi insert within duct 20 serves to provide a region of increased velocity and reduced pressure over the velocities and pressures achieved in the duct disclosed in Figure 1.

It will be understood that the relative cross sectional dimensions of duct '20, opening 56 of ram tube 52, feed line 50, and orifice 22, as well as those of the associated passages of the fiow path will be selected in accordance with the cooling requirements of the engine. Under normal full load operating conditions of the engine, coolant is transferred to the engine cylinder water jacket at a flow rate to insure operation under steaming conditions.

The cooling system of the present invention serves to maintain a substantially constant temperature of the engine cylinders during operation of the engine. Further, the coolant is circulated through both the engine jacket and through the heat exchange devices without the use of valves, pumps, or other accessories having moving parts. As has heretofore been discussed, the amount of water circulated through the engine jacket is dependent upon the velocity of the steam flowing in duct 29 or through the Venturi orifice, and this velocity is in turn dependent upon the operating temperatures of the engine. Thus, the flow of coolant through the engine jacket is a function of the output or load of the engine. The improved coolant circulatory system has the further advantage that the cooling capacity of the volume of water in the radiator is suflicient to continue the jet condensing and circulating action for a period of time after the engine has ceased operation. This continued flow 7 of coolant serves to absorb the residual heat of through which steam flows in a stream at high velocity and at a pressure below the average ambient pressureof the system, orifice means in said discharge duct through which a liquid coolant is introduced into said duct to intermix with said steam in the flow stream, and a feed line communicating between the high velocity region of the flow stream withinsaid discharge duct and said water jacket through which coolant is de- 7 livered to said jacket by the impact force of the r 2. In a coolant circulatory system for an internal combustion engineprovided with a water jacket within which steam is generated during the operation of said engine, the combination comprising a duct connected to said water jacket through which steam generated in said jacket flows at a high velocity'and at a pressure below the average pressure of the system, an orifice positioned in said duct, a heat exchange device having the intake thereof connected to receive the discharge of said duct, conduit means connecting. the outlet of said device to said-orifice whereby steam flowing through said heat ex change device is cooled and the liquid coolant is returned to the reducedpressure region in said duct to intermix with steam issuing from said water jacket, and a feedline having the. intake thereof positioned within the duct to receive the impact of high velocity flow ofsaid intermixed steam and condensate and the outlet thereof connected to said water jacket.

3. In a coolant circulatory system for an in ternal combustionengine provided with a water erated in said jacket flows at a high velocity and at a pressure below the average pressure of the system, an orificepositioned in duet, a radiator having theupper portion thereof in communication with the outlet of said condenser tank and the lower portion thereof connected to orifice whereby the coolant flowing thro h said radiator is introduced into said duct to intermix with the steam issuing from said water jacket, and means to conveycooiant-to water jacket comprising a-feed line having the intake thereof positioned within said duct to receive the impact of the high-velocity fiow stream of said intermixed steam and liquid coolant and the outlet thereof connected to said water jacket.

4. In a coolant circulatory system for an internal combustion engine provided with a water jacket within which steam is generated during operation of said engine,-the combination comprising a condenser tank provided with an outlet positioned above the normal cold water level in the system, a duct positioned below the normal cold Water level of the system connecting said water jacket and condenser tank, an orifice in said duct, a radiator having a vapor connection between an upper header thereof and the outlet of said condenser tank and a lower header connected by a condensate return line tosaid orifice, a feed line discharging into said water jacket having the intake thereof positioned within said duct and directed toward the water jacket connection, and means for. maintaining the pressure in the system above atmospheric pressure during circulation of the coolant through said radiator and said feed line.

5. In a coolant circulatory systemifor an. internal combustion engine provided with a .water jacket within which steam is generated during the operation of the enginal the combination comprising, a Venturi jet circulator having the intake thereof connected to receive the steam issuing from said water jacket, a flow passage from the outputof said jet circulator to the reduced pressure region ofsaid jet comprising a heat exchange device wherein the coolant is cooled and returned to the jet circulatorv to intermix with the steam issuing from said jacket, and a, feed line connected to supply coolantto said water jacket having the intake thereof positioned in the outlet of the Venturi jet whereby coolant is delivered to the water jacket by the impact force of the jet stream.

6. In a coolant circulatory system for an internalcombustion engine provided with a water jacket within which steam is generated during the operation of the engine, the combination comprising a Venturi jet circulator'having the intake thereof connected to receive the steam issuing from said water jacket, a flow passage from the output of said jet circulator to thereduced pressure region of said jet comprising a heat exchange device wherein the .coolantis cooled and returned to the jet circulate! to intermix with the steam issuing from said jacket, as feed line connected to supply coolant to said water jacket having the intake thereof positioned in the outlet of the Venturi jet whereby coolant is delivered to the water jacket by the impact force of the jet stream, and venting means for said system comprising a spring biased .valvefor maintaining the pressure in the system above atmospheric pressure during operation of the engine.

' 7. In a coolant circulatory system for an internal combustion engine provided with a water jacket within which steam is generated during operation of said engine, the combinationcomprising a condenser tank provided with an'inlet and an outlet, a Venturi jet circulator having the intake thereof connected to receive steam issuing from said water jacket and the outlet thereof connected to said condenser tank inlet, a radiator having the upper portion thereof in communication with the outlet of said condenser tank and the lower portion thereof connected with the reduced pressure region of said jet whereby coolant cooled in said radiator is fed to and intermixed with steam issuing from said water jacket, and

means to convey coolant to said water jacket comprising a feed line having the intake thereof positioned in the outlet of the Venturi jet whereby coolant is delivered to the water jacket by the impact force of the jet stream.

8. Ina coolant circulatory system foran internal combustion engine provided with a water jacket within which steam is generated during operation of said engine, the combination comprising a condenser tank provided with anputlet positioned above the normal cold water level in the system, a Venturi jet circulator positioned below the normal cold water level of the coolant and connected between the outlet of said water jacket and the inlet of said condenser tank, a radiator having a vapor connection between an upper header thereof and the outlet of said condenser tank and a lower header connected by a condensate return line to the low pressure region of said Venturi jet circulatonand a conduit having 'the outlet thereof connected to the water jacket and the inlet thereof located below the normal cold water level of the system and positioned in the outlet of the Venturi jet circulator.

9. In a coolant circulatory system for an internal combustion engine'provided with a water jacket within which steam is generated during operation of said engine, the combination comprising a condenser tank provided with an outlet positioned above the normal cold water level of the system, a Venturi jet circulator positioned below the normal cold water level of the coolant and connected between the outlet of said Water jacket and the inlet of said condenser tank, a radiator having a vapor connection between one header thereof and the outlet of said condenser tank and another header connected by a condensate return line to the low pressure region of said Venturi jet circulator, a feed line having the outlet thereof connected to the water jacket and the inlet thereof located below the normal cold water level of the system and positioned in the path of the Venturi jet adjacent to the outlet thereof, and venting means positioned in said feed line to permit the escape of entrapped gas.

10. In a coolant circulatory system for an internal combustion engine provided with a water jacket within which steam is generated during the operation of said engine, the combination comprising a duct connected to said water jacket through which steam generated in said jacket flows at a high velocity and at a pressure below the average ambient pressure of the system, an orifice positioned. in said duct, a heat exchange device having the intake thereof connected to receive the discharge of said duct, conduit means connecting the outlet of said device to said orifice whereby coolant flowing through said heat exchange device is cooled and returned to the reduced pressure region in said duct to intermix with steam issuing from said water jacket, a feed line having the intake thereof positioned within the duct to receive the impact of the high velocity flow path of said intermixed steam and condensate and the outlet thereof connected to said water jacket, and venting means positioned in said feed line to permit the escape of entrapped gas.

11. In a coolant circulatory system for an internal combustion engine provided with a water jacket within which steam is generated during operation of the engine, the combination comprising a condenser tank provided with an inlet and an outlet, a tubular duct having the inlet thereto connected to said water jacket and positioned to discharge the steam generated in said jacket to the inlet of said condenser tank, an orifice positioned in the wall of said duct, an annular member positioned within said duct provided with apertures located in the wall of said member adjacent to one end thereof and having a diverging passage extending from said apertures to the mouth of the member with a fluid path extending from said orifice to said apertures, a radiator having the upper portion thereof in communication with the outlet of said condenser tank and the lower portion thereof connected to said orifice, and a feed line discharging into said water jacket having the intake thereof positioned within the mount of said annular member and directed toward the inlet of said duct.

12. In a coolant circulatory system for an internal combustion engine provided with a water jacket within which steam is generated during operation of the engine, the combination com prising a condenser tank provided with an inlet and an outlet, a tubular duct having the inlet thereto connected to said water jacket and positioned to discharge the steam generated in said jacket to the inlet of said condenser tank, an orifice positioned in the wall of said duct, an annular member positioned within said duct provided with apertures located in the wall of said member adjacent to one thereof and having a diverging passage extending from said apertures to the mouth of the member with a fluid path extending from said orifice to said apertures, a radiator having the upper portion thereof in communication with the outlet of said condenser tank and the lower portion thereof connected to said orifice, a feed line discharging into said water jacket having the intake thereof -positioned. within the mouth of said annular member and directed toward the inlet of said duct, and venting means for said feed line positioned to discharge entrapped gas into said condenser.

ARTHUR W. POPE, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,168,172 Culver Jan. 11, 1916 1,346,331 Muir July 13, 1920 1,485,390 Gowing Mar. 4, 1924 1,571,108 Diamant Jan. 26, 1926 1,632,581 Barlow June 14, 1927 1,651,157 Rushmore Nov. 29, 1927 

